The invention relates to a method for processing a data flow according to the content thereof. The method therefore enables the data flow to be processed in different ways according to the nature of the content thereof. The method may be used in particular on processors for controlling data flow.
At present, by means of services offered on the Internet, such as—for example—the Kazaa network and free exchange services such as BearShare or Audiogalaxy, it is possible for data to be stored and made accessible—not on a central server, but for data stored locally on a user processor to be made available for searching and transferable to a different user processor. This is known as file sharing. In the case of Napster, for example, all files and users are placed on an extensive central index for this purpose. The files are then exchanged directly between the users.
It is always difficult to differentiate data flows with copyright-protected content from those without copyright-protected content. In a peer-to-peer network in particular, such as is implemented in Napster, for example, it is difficult to make the forwarding of data flows dependent on the nature of the content.
Thus, for example, European patent EP 0 784 838 B1 discloses a method wherein a data flow is compared with a list of known data flows, and wherein—if said data flow is recognized as a known data flow—it is further processed according to a predefined manner, e.g. by alerting a police patrol. Often, however, the problem remains of what to do with the data flow if a match cannot be found with any of the list entries. A further method for detecting copyright-protected data is disclosed by European patent application EP 1 079 627 A1. This method, however, is based on the recognition of a digital watermark in the data flow which has been added to the data flow beforehand. This method cannot therefore be used for data flows that do not have such a digital watermark.